User Manual

AirLink Pro T1/E1 Rack Mount Installer’s Guide
Glossary
Rev. B - 1/97
D-4
level of the DS1 (T1), DS2 (T2), and DS3 levels of the North
American digital hierarchy.
DTE Data Terminating Equipment. A communication device that
is the source or destination of signals on a network.
dynamic range The difference between the maximum receiver input signal
and the minimum receiver input signal level (receiver
sensitivity). The measure of the maximum achievable fade
margin of a radio system.
Errored Second (ES) An errored second is defined as any one-second interval during
which there is one or more CRC-16 errors. Errored seconds can
be asynchronous, that is, they do not have to be correlated
with real time.
Errored Seconds Threshold This threshold value is compared to the number of Errored
Seconds in the current time interval. That is, when the
number of Errored Seconds crosses the specified threshold
value, an alarm message is generated.
ESF Error Event An ESF Error Event occurs when an Extended Superframe
contains a CRC-16 Error Event, or when an Out-of-Frame
(OOF) state occurs.
fade margin The measure of how much signal attenuation the system can
endure without dropping below the minimum desired BER
level.
Framing Insertion of framing bits that signal the beginning of a framed
block of data. For example, in D4 transmissions there are 12
frame sequences of data identified by a unique framing bit—
the 193rd bit in the sequence— that carries the framing and
signaling information.
free space path loss The loss of power of a radiated signal as it travels through
space.
frequency stability The measure of frequency variation of an oscillator from its
assigned operational mean frequency.
gain The increase in signal power caused by a device or network
(e.g., the signal gain provided by an antenna).
GHz
Gigahertz; 1 billion, or 10
9
cycles per second.